Beneficial effects of Ribes nigrum L. polyphenols on yogurt: Sensory quality, probiotic proliferation, pathogen...

Yogurt is a globally popular fermented dairy product with excellent nutritional value. Its well-documented health benefits are predominantly associated with the probiotic strains involved in the fermentation process, which play key roles in gut microbiota modulation and metabolic homeostasis regulation. Concurrently, polyphenols derived from Ribes nigrum L. (RMAP) are likewise recognized for their bioactive potential, particularly their antioxidant and antimicrobial activities. To meet growing consumer interest and demand for value-added yogurt, the polyphenols extracted from Ribes nigrum L. (RMAP) were processed into freeze-dried powder and incorporated into yogurt to develop a novel functional product. After 21 days of storage at 4 °C, the addition of RMAP (0.25% ∼ 4%, w/w) in yogurt significantly promoted the viability of probiotic lactobacilli (L. plantarum, L. casei, L. rhamnosus, and L. acidophilus), improved the sensory property, antioxidant and α-glucosidase inhibitory activities, and inhibited the biofilm formation of pathogenic bacteria (S. aureus, E. coli and Salmonella). Moreover, the incorporation of RMAP suppressed protein degradation and stabilized the structure of protein in yogurt. Especially, the yogurt with 2% RMAP displayed the superior sensory quality, physicochemical characteristics and stability. UPLC-ESI-MS analysis revealed that yogurt supplemented with RMAP contained elevated levels of antioxidant compounds, including protocatechuic acid, rutin, and hyperoside. Principal component analysis demonstrated that the microbial stability, flavor quality, antioxidant activity, and overall sensory of RMAP-fortified yogurt were closely associated with the storage time. Therefore, RMAP may be a promising supplement for the development of innovative functional dairy products with enhanced nutritional and bioactive profiles.